Vowel deletion in Yine crucially refers to both morphological and phonological information. It has been argued that the process is only analysable in a theory where the phonology has access to morphology, either on the assumption of different morphological domains of constraint evaluation (Lin 1987, 1997a, b) or on the assumption of morphologically indexed optimality-theoretic constraints (Pater 2009). In contrast, I propose a phonological analysis of vowel deletion in Yine in a parallel Optimality Theory model. The phonology, I assume, has only limited access to morphological information, and can only distinguish between affix and stem material. I argue that the morphemes that trigger deletion of a preceding vowel have a defective underlying representation: they lack a mora, and ‘usurp’ the mora of a preceding vowel.